The purposes of the Adipocyte Core are to assist Boston Obesity/Nutrition Research Center members by: 1. Preparing human and experimental animal cultured preadipocytes, fat cells, and products of these cells (including DNA, RNA, protein, and conditioned medium) and maintaining a human and rodent preadipocyte bank and database. With expansion of the Core, it will also become feasible to provide transiently transfected human and rodent preadipocytes (using adenoviral vectors) and stably transfected human preadipocyte strains (on the background of telomerase-expressing human preadipocytes) as the requisite methods are developed, 2. Providing consultative advice about experimental design, IRB documentation, and methods involving these cells and products, and teaching investigators and members of their laboratories about the preparation of fat cells, preadipocytes, and products of these cells from humans and experimental animals. 3. Supporting the Adipose Tissue Study Group (a seminar series run by the Core), fostering collaborative links among investigators in adipocyte biology, and continuing to provide assistance to investigators new to the field.